POS0978 EXPLORING SMARTPHONE-BASED DIGITAL ENDPOINTS FOR RHEUMATIC CONDITIONS
Authors: R. Araújo, P. Matias, P. Studenic, M. Valada, R. Graca, N. Nakhost Lotfi, D. Belo, F. Nunes
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> The care of rheumatic diseases is currently episodic, based on visits every 3-6 months at the rheumatologist, which may fail to characterize the condition state. To address this issue, the research community is investigating ways to use smartphones and sensors to monitor conditions passively. <h3>Objectives</h3> Explore associations between smartphone-generated data, standardized functional tests, and Patient Reported Outcome Measures (PROMS) to support the creation of digital endpoints. <h3>Methods</h3> Participants from Portugal and Austria participated in a Data Collection that included: (i) physical activities, such as walking with a smartphone in the pocket; (ii) hand dexterity exercises, such as copying text sentences with the smartphone keyboard; (iii) downloading and processing sociability data from the participants' smartphone; (iv) performing functional tests, such as Moberg Pickup Test (Moberg) and Timed Up-and-Go (TUG); and (v) answering validated PROMS, such as MD-HAQ, EQ-5D-5L, and visual analogue scale (VAS) for pain, fatigue, and disease activity. Statistical analysis focused on the correlation between smartphone-collected data and functional tests or PROMs, and independent t-test for between-group comparison. <h3>Results</h3> We collected data from 59 participants (76% female, 24% male). From this set, 31 were patients diagnosed with osteoarthritis (45%), rheumatoid arthritis (26%), or psoriatic arthritis (29%). The remaining 28 were age-matched healthy controls. In terms of age, 17% of participants were under 41 years old, 52% were between 41 and 60, and 31% were 61 or older. Most patients reported stiffness or pain in the upper (90%) and lower (83%) parts of the body. Subjective health status was high (M=77.95, SD= 16.31) in the VAS of EQ-5D-5L. Independent t-tests (Table 1) showed significant differences between patient and control groups regarding Mobility (M= 1.90, SD= 0.77), Pain/Well-Being (M= 2.48, SD= 0.81), and Mental Health (M= 1.68, SD=0.83) with higher difficulty levels reported by rheumatic patients compared to controls. Rheumatic patients also rated worse in HADS anxiety (M= 5.90, SD= 3.74) but not depression. We found significant differences between patients and controls in the variability of key pressing time (ms), with less variability among patients than controls (M= 30.71, SD= 11.99). The inter-key typing time was lower in participants below 50 years than above. A moderate correlation was found between the number of character deletions and the Moberg test (r= 0.44, p = 0.02) in patients with hand joint pain. Regarding Mobility associations, TUG total time (s) was positively correlated with the number of total steps (r=0.81, p &lt;.001), the average duration (s) of each step (r= 0.35, p &lt;.001), the average speed (m/s) of walking (r= -0.92, p &lt;.001), as well as the standing up (r= 0.59, p &lt;.001) and sitting down (r=0.55, p &lt;.001) times (s). <h3>Conclusion</h3> Data collection with smartphone appears to have face, construct and discriminative validity, able to support future trials in patients with rheumatic diseases, to validate smartphone-based data vs objective measures of disease activity and quality of life over time. <h3>Acknowledgements</h3> This research was supported by the project COTIDIANA (AAL2020-7-146-CP) funded under the AAL Joint Programme, by the European Commission and the National Funding Authorities of Portugal, Austria, and Switzerland. <h3>Disclosure of Interests</h3> Ricardo Araújo: None declared, Pedro Matias: None declared, Paul Studenic Speakers bureau: AstraZeneca, Maria Valada: None declared, Ricardo Graca: None declared, Nasim Nakhost Lotfi: None declared, David Belo: None declared, Francisco Nunes: None declared.